TRIM31 and bladder transitional cell carcinoma: The ubiquitin‐proteasome system is critical for tumors and influences the protein stability of several key molecules associated with tumorigenesis, progression, metastasis, and chemotherapy resistance.[4] Our previous studies confirmed several E3 ligases that are strongly associated with BLCA proliferation and metastasis.[5] The RING finger (RNF) protein family comprises important E3 ligases.